App: GeoFeature/ComplexGeoData API changes

These are the bare minimum set of APIs for future new topogical naming
feature (see [here](https://git.io/fj6hy) for a overview of the new
APIs).

These APIs are added early to avoid too much code change for the new
features introduced in the current patch set.

src/App/ComplexGeoData.cpp

@@ -27,7 +27,10 @@
 # include <cstdlib>
 #endif
 
+#include <boost/algorithm/string/predicate.hpp>
 
+#include <Base/Exception.h>
+#include <Base/Console.h>
 #include "ComplexGeoData.h"
 
 using namespace Data;
@@ -39,6 +42,7 @@ TYPESYSTEM_SOURCE_ABSTRACT(Data::ComplexGeoData , Base::Persistence);
 
 
 ComplexGeoData::ComplexGeoData(void)
+    :Tag(0)
 {
 }
 
@@ -153,3 +157,97 @@ bool ComplexGeoData::getCenterOfGravity(Base::Vector3d&) const
 {
     return false;
 }
+
+const std::string &ComplexGeoData::elementMapPrefix() {
+    static std::string prefix(";");
+    return prefix;
+}
+
+const char *ComplexGeoData::isMappedElement(const char *name) {
+    if(name && boost::starts_with(name,elementMapPrefix()))
+        return name+elementMapPrefix().size();
+    return 0;
+}
+
+std::string ComplexGeoData::newElementName(const char *name) {
+    if(!name) return std::string();
+    const char *dot = strrchr(name,'.');
+    if(!dot || dot==name) return name;
+    const char *c = dot-1;
+    for(;c!=name;--c) {
+        if(*c == '.') {
+            ++c;
+            break;
+        }
+    }
+    if(isMappedElement(c))
+        return std::string(name,dot-name);
+    return name;
+}
+
+std::string ComplexGeoData::oldElementName(const char *name) {
+    if(!name) return std::string();
+    const char *dot = strrchr(name,'.');
+    if(!dot || dot==name) return name;
+    const char *c = dot-1;
+    for(;c!=name;--c) {
+        if(*c == '.') {
+            ++c;
+            break;
+        }
+    }
+    if(isMappedElement(c))
+        return std::string(name,c-name)+(dot+1);
+    return name;
+}
+
+std::string ComplexGeoData::noElementName(const char *name) {
+    auto element = findElementName(name);
+    if(element)
+        return std::string(name,element-name);
+    return name;
+}
+
+const char *ComplexGeoData::findElementName(const char *subname) {
+    if(!subname || !subname[0] || isMappedElement(subname))
+        return subname;
+    const char *dot = strrchr(subname,'.');
+    if(!dot)
+        return subname;
+    const char *element = dot+1;
+    if(dot==subname || isMappedElement(element))
+        return element;
+    for(--dot;dot!=subname;--dot) {
+        if(*dot == '.') {
+            ++dot;
+            break;
+        }
+    }
+    if(isMappedElement(dot))
+        return dot;
+    return element;
+}
+
+const std::string &ComplexGeoData::tagPostfix() {
+    static std::string postfix(elementMapPrefix() + ":T");
+    return postfix;
+}
+
+const std::string &ComplexGeoData::indexPostfix() {
+    static std::string postfix(elementMapPrefix() + ":I");
+    return postfix;
+}
+
+const std::string &ComplexGeoData::missingPrefix() {
+    static std::string prefix("?");
+    return prefix;
+}
+
+bool ComplexGeoData::hasMissingElement(const char *subname) {
+    if(!subname)
+        return false;
+    auto dot = strrchr(subname,'.');
+    if(dot)
+        subname = dot+1;
+    return boost::starts_with(subname,missingPrefix());
+}

src/App/ComplexGeoData.h

@@ -156,6 +156,41 @@ public:
     virtual bool getCenterOfGravity(Base::Vector3d& center) const;
     //@}
 
+    /** @name Element name mapping */
+    //@{
+    /// Sepecial prefix to mark the begining of a mapped sub-element name
+    static const std::string &elementMapPrefix();
+    /// Sepecial postfix to mark the following tag
+    static const std::string &tagPostfix();
+    /// Speical postfix to mark the index of an array element
+    static const std::string &indexPostfix();
+    /// Speical prefix to mark a missing element
+    static const std::string &missingPrefix();
+    /// Check if a subname contains missing element
+    static bool hasMissingElement(const char *subname);
+    /** Check if the name starts with elementMapPrefix()
+     *
+     * @param name: input name
+     * @return Returns the name stripped with elementMapPrefix(), or 0 if not
+     * start with the prefix
+     */
+    static const char *isMappedElement(const char *name);
+
+    /// Strip out the trailing element name if there is mapped element name preceeds it.
+    static std::string newElementName(const char *name);
+    /// Strip out the mapped element name if there is one.
+    static std::string oldElementName(const char *name);
+    /// Strip out the old and new element name if there is one.
+    static std::string noElementName(const char *name);
+
+    /// Find the start of an element name in a subname
+    static const char *findElementName(const char *subname);
+
+    static inline const char *hasMappedElementName(const char *subname) {
+        return isMappedElement(findElementName(subname));
+    }
+    //@}
+
 protected:
 
     /// from local to outside
@@ -171,6 +206,8 @@ protected:
         Base::Vector3d tmp = tmpM * vec;
         return Base::Vector3f((float)tmp.x,(float)tmp.y,(float)tmp.z);
     }
+public:
+    mutable long Tag;
 };
 
 } //namespace App

src/App/ComplexGeoDataPy.xml

@@ -37,5 +37,11 @@
 		  </Documentation>
 		  <Parameter Name="Matrix" Type="Object" />
 	  </Attribute>
+      <Attribute Name="Tag">
+          <Documentation>
+              <UserDocu>Geometry Tag</UserDocu>
+          </Documentation>
+          <Parameter Name="Tag" Type="Int"/>
+      </Attribute>
   </PythonExport>
 </GenerateModel>

src/App/ComplexGeoDataPyImp.cpp

@@ -126,6 +126,14 @@ void  ComplexGeoDataPy::setMatrix(Py::Object arg)
     }
 }
 
+Py::Int ComplexGeoDataPy::getTag() const {
+    return Py::Int(getComplexGeoDataPtr()->Tag);
+}
+
+void ComplexGeoDataPy::setTag(Py::Int tag) {
+    getComplexGeoDataPtr()->Tag = tag;
+}
+
 PyObject *ComplexGeoDataPy::getCustomAttributes(const char* /*attr*/) const
 {
     return 0;

src/App/GeoFeature.cpp

@@ -79,3 +79,62 @@ PyObject* GeoFeature::getPyObject(void)
     }
     return Py::new_reference_to(PythonObject);
 }
+
+
+std::pair<std::string,std::string> GeoFeature::getElementName(
+        const char *name, ElementNameType type) const
+{
+    (void)type;
+
+    std::pair<std::string,std::string> ret;
+    if(!name) return ret;
+
+    ret.second = name;
+    return ret;
+}
+
+DocumentObject *GeoFeature::resolveElement(DocumentObject *obj, const char *subname, 
+        std::pair<std::string,std::string> &elementName, bool append, 
+        ElementNameType type, const DocumentObject *filter, 
+        const char **_element, GeoFeature **geoFeature)
+{
+    if(!obj || !obj->getNameInDocument())
+        return 0;
+    if(!subname)
+        subname = "";
+    const char *element = Data::ComplexGeoData::findElementName(subname);
+    if(_element) *_element = element;
+    auto sobj = obj->getSubObject(subname);
+    if(!sobj)
+        return 0;
+    obj = sobj->getLinkedObject(true);
+    auto geo = dynamic_cast<GeoFeature*>(obj);
+    if(geoFeature) 
+        *geoFeature = geo;
+    if(!obj || (filter && obj!=filter))
+        return 0;
+    if(!element || !element[0]) {
+        if(append) 
+            elementName.second = Data::ComplexGeoData::oldElementName(subname);
+        return sobj;
+    }
+
+    if(!geo || hasHiddenMarker(element)) {
+        if(!append) 
+            elementName.second = element;
+        else
+            elementName.second = Data::ComplexGeoData::oldElementName(subname);
+        return sobj;
+    }
+    if(!append) 
+        elementName = geo->getElementName(element,type);
+    else{
+        const auto &names = geo->getElementName(element,type);
+        std::string prefix(subname,element-subname);
+        if(names.first.size())
+            elementName.first = prefix + names.first;
+        elementName.second = prefix + names.second;
+    }
+    return sobj;
+}
+

src/App/GeoFeature.h

@@ -66,7 +66,48 @@ public:
      * @return the Python binding object
      */
     virtual PyObject* getPyObject(void);
-       
+
+    /// Specify the type of element name to return when calling getElementName() 
+    enum ElementNameType {
+        /// Normal usage
+        Normal=0,
+        /// For importing
+        Import=1,
+        /// For exporting
+        Export=2,
+    };
+    /** Return the new and old style sub-element name
+     *
+     * @param name: input name
+     * @param type: desired element name type to return
+     *
+     * @return a pair(newName,oldName). New element name may be empty.
+     *
+     * This function currently is does nothing. The new style element name
+     * generation will be added in the next batch of patches.
+     */
+    virtual std::pair<std::string,std::string> getElementName(
+            const char *name, ElementNameType type=Normal) const;
+
+    /** Resolve both the new and old style element name
+     *
+     * @param obj: top parent object
+     * @param subname: subname reference 
+     * @param elementName: output of a pair(newElementName,oldElementName)
+     * @param append: Whether to include subname prefix into the returned
+     *                element name
+     * @param type: the type of element name to request
+     * @param filter: If none zero, then only perform lookup when the element
+     *                owner object is the same as this filter
+     * @param element: return the start of element name in subname
+     *
+     * @return Return the owner object of the element
+     */
+    static DocumentObject *resolveElement(App::DocumentObject *obj, 
+            const char *subname, std::pair<std::string,std::string> &elementName, 
+            bool append=false, ElementNameType type=Normal,
+            const DocumentObject *filter=0,const char **element=0, GeoFeature **geo=0);
+
     /**
      * @brief Calculates the placement in the global reference coordinate system
      *